Remains of a 13th century tower which was part of the Dublin City wall have been discovered on Essex Quay.
Islodes Tower, built in the 13th century, was the most important tower in the walls that surrounded Norman Dublin, which was the first line of defence against invaders travelling up the River Liffey.
The archaeologists knew the tower was there but the maps played the tricks.
The tower was discovered eight metres from where the archaeologists thought it to be. Weeks of digging have revealed a circular tower at foundation level with walls over three metres thick.
It is believed that the main tower was demolished during the 17th century to make way for the construction of houses. In May 1993, these houses were torn down and excavations began revealing the remains of Isoldes Tower.
Archaeologist Margaret Gowan spoke to RTÉ News about uncovering the remains of the tower after three hundred years.
We know precisely what size it is, what shape it is, and where it is.
Temple Bar Properties hope to integrate the remains of the tower into the proposed development for the site.
The location of the tower has meant that developers have to go back to the drawing board in relation to what they build on the site.
An RTÉ News report broadcast on 23 July 1993. The reporter is Una O'Hagan.